Chemical speciation and equilibria of some nucleic acid compounds and their iron(III) complexes
| Autor: | Mamdouh S. Masoud, Amina A. Soayed, Ahmed M. Hindawy, Marwa Y. Abd El-Kaway |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Purine
Absorption spectroscopy Chemistry Stereochemistry Barbital Tautomer Medicinal chemistry Ferric Compounds Atomic and Molecular Physics and Optics Analytical Chemistry chemistry.chemical_compound Pyrimidines Isomerism Stability constants of complexes Purines Spectrophotometry Nucleic Acids medicine Nucleic acid Phenol Instrumentation Spectroscopy Stoichiometry medicine.drug |
| Zdroj: | Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy. 92 |
| ISSN: | 1873-3557 |
| Popis: | The pH effect on electronic absorption spectra of some biologically active nucleic acid constituents have been studied at room temperature and the mechanism of ionization was explained. These compounds are of two categories (pyrimidines: [barbital; 5,5′-diethyl-barbituric acid], [SBA; 4,6-dihydroxy-2-mercapto-pyrimidin], [NBA; 5-nitro-2,4,6(1H,3H,5H)-pyrimidine trione] and [TU; 2,3-dihydro-2-thioxo-pyrimidin-4(1H)-one]) and (purines: [adenine; 6-amino purine], its [Schiff bases derived from adenine-acetylacetone; (Z)-4-(7H-purin-6-ylimino)pentan-2-one) and adenine-salicylaldehyde; 2-((7H-purin-6-ylimino) methyl) phenol] and its [Azo derived from adenine-resorcinol; 4-((7H-purin-6-yl)-diazenyl) benzene-1,3-diol]. The phenomena of tautomerization assigned different tautomers. Different spectrophotometric methods are applied to evaluate the pK's values that explained with their molecular structures. The interaction of Fe3+ with some selected pyrimidines (barbital, NBA and SBA) was explained using familiar six spectrophotometric methods. The data typified the existence of different absorbing species with the different stoichiometries 1:1, 1:2, 1:3 and 2:3. The stability constant of the complexes was computed. More approach was deduced to assign the existence of different species applying the distribution diagrams. |
| Databáze: | OpenAIRE |
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